An operating machine driven by an engine, such as an engine generator (in the following description, typified as “engine generator”) is provided with buffer means so that an impact of external force is not directly transmitted from an external frame to the body of the engine generator or, reversibly, vibration of the engine is not transmitted to the external frame.
For example, Japanese Unexamined Patent Application Publication No. 06-81897 discloses a device for mounting a generator, provided in such a manner that an elastic member such as rubber is interposed between a frame-side plate and a generator-side plate and a pin projected from the generator-side plate is positioned between a pair of stoppers provided for the frame-side plate. In the mount device, in the case where external force acts on the generator, it is buffered by the elastic member, and the pin comes into contact with the stoppers to regulate the motion of the generator.
Japanese Utility Model Registration No. 3,065,007 discloses an engine generator having a generator base and a common base supporting a generator and an engine, and having a structure that the generator base and the common base are loosely fit while interposing a vibration-proof rubber between the bases. In the engine generator, the generator base and the common base are attached with a sufficient space therebetween so that the generator base and the common base do not come into contact with each other and become a noise source when the engine vibrates.
A mount device with buffer means or an elastic member as described in Japanese Unexamined Patent Application Publication No. 06-81897 and Japanese Utility Model Registration No. 3,065,007 mainly functions as a member of fixedly supporting a lower part of an engine generator to a base member or a frame. In addition, in some cases, using a position regulating plate as a metal plate provided for an upper part of the engine generator (hereinbelow, called “bump stopper”), a shake of the upper part is regulated. Generally, the engine generator is surrounded by an external frame. For example, there is a case that the engine generator shakes in a shake width larger than that in normal operation due to vibration of a transport vehicle during transportation, shake of a transportation crane, or the like. Consequently, to prevent a part of the engine generator from being come off from the external frame to the outside, a bump stopper is provided. When the engine generator largely shakes, the bump stopper comes into contact with the external frame to regulate the position so that the engine generator does not come off from the external frame to the outside.
The gap between the bump stopper and the external frame of the engine generator is set so that, when the external frame is subjected to impact from the outside, the bump stopper comes into contact with the external frame faster than the other members. With the configuration, avoiding direct contact of the engine generator body with the external frame, the engine generator is protected.
FIG. 8 is a diagram showing an example of a conventional position regulating apparatus using a bump stopper. In FIG. 8, a bump stopper 200 is a piece of a metal plate (for example, a steel plate) and has a main part 201 and reinforcement members 202, 203, and 204 orthogonal to the main part 201. In this example, the reinforcement member 202 is an attachment part whose sectional shape is an L shape suited to attach the bump stopper 200 to an engine 205. The bump stopper 200 is fixed to the engine 205 using a bolt 206 passed through the attachment part 202. The reinforcement member 204 of the bump stopper 200 is disposed in a position opposed to a bracket 207, and the bracket 207 is attached to a horizontal part of a beam 209 as a part of an external frame of an engine generator with a bolt 210 penetrated from below.
With the bump stopper 200 of FIG. 8, in the case where the engine generator vibrates vertically or horizontally in the diagram or in the case such that the beam 209 is deformed by application of an external force F, the tip of the bump stopper 200, that is, the reinforcement member 204 side of the bump comes into contact with the bracket 207, so that the external force transmitted from the beam 209 is not directly transmitted to the engine 205. Since the bump stopper 200 comes into contact with the beam 209, even when vibration having large amplitude is applied, a movable part of the engine generator is prevented from being come off from the external frame to the outside.